I don't know much about the sets, but I do have the Swingblade and the RazorBlaze.

The Swingblade was the first one I got and immediately after using it the first time bought one for my brother and my dad. They are sharp and hold an edge very well. The RazorBlaze has the replaceable blades. They are just as sharp as the Havalon. It has the Havalon beat in that the blade holder provides some backup to the blade, but it does get "gunked up" which can make the blades hard to remove and is not super easy to clean.